He needs to be challenged and I don't think the jump to high A will do that.
I never really understood the Greenville promotion as opposed to Salem at the time. What was to be gained from pretty much a sideways promotion, unless there was a Drive pitching coach or the like they wanted him to develop under? Otherwise, it seems like he's being jerked from one team to another in a short time frame
I think both of you are incorrect in the assumption that a single jump is pretty much a lateral promotion. This does not mean that a certain player (we will call him Durbin in this case) could double jump and be fine... but let's look at some numbers. First, Durbin.
SSA: 4 IP, 7 K, 13 Batters faced, 1 Batter reached via an error. In the three games where pitches were compiled, he had a 75% strike rate (30/40)
Clearly dominant. Clearly in need of a move forward.
A: 7 IP, 14K, 6 H (3 1B, 2 2B, 1 3B), 1 BB, 3 R/2 ER. Opposition: .214/.241/.357, .429 BABIP. 69% strike percentage.
Still largely ridiculous. But, not super-hero dominant. Players were able to hit him. He suffered a loss, gave up a couple of runs. It probably would not be useful to keep him in Greenville longer, but I don't think putting him there hurt him in any way.
The lack of general promotion/demotion in the Red Sox system leaves us a little barren in terms of pitchers from this season with jumps (with some level of consistent play at a level)... but we have one in Hunter Haworth. Now, Hunter is no Durbin Feltman. He was a 22nd round pick in 2017 out of Cal-State Chico and started his professional career in the GCL last season.
However, the Sox started him at Greenville to begin the year and gave him four starts. Haworth put up a line of 0-3 with a 12.06 ERA over 15 2/3 innings. He gave up 32 hits (18 1B, 7 2B, 2 3B, 5 HR), 8 BB, 1 HBP, and 16 K. Opp: .395/.456/.716, .450 BABIP.
He was then put on a shelf until June. He had relief appearance for the Drive on 6/13 before being going to Lowell. In Lowell, he has put up a line of 2-3 with a 3.66 ERA. 32 IP, 29 H (18 1B, 8 2B, 1 3B, 2 HR) with 12 BB and 37 K. Opp: .238/.301/.369, .318 BABIP.
Now, obviously Haworth is not a pure analog for Feltman. However, it does show how a pitcher can do reasonably well in one league and have completely catastrophic performances in one league above.
For a somewhat purer analog, we'll go to 2016. Where we take up the case of a chap named Bobby Poyner.
Greenville (4/9-5/30): 16 G, 26 IP, 0-0, 11 saves, 0.35 ERA, 11 H (9 1B, 1 2B, 1 3B), 0 BB, 0 HBP, 32 K, 2 R/1 ER. Opp: .128/.128/.163, .204 BABIP.
Salem (6/2-9/3): 23 G, 39 2/3 IP, 3-1, 4 saves, 4.99 ERA, 44 H (30 1B, 7 2B, 3 3B, 4 HR), 11 BB, 1 HBP, 30 K, 24 R/22 ER. Opp: .278/.324/.437, .315 BABIP.
Is/Was Poyner as big of a prospect as Feltman? Maybe not. He was a 14th round draft pick but out of a pretty decent college (Florida). But, he needed a full year at Salem after dominating in Greenville.
We don't know where Feltman will encounter real resistance with his stuff. Maybe nowhere. But there is a reason the minor leagues are structured as they are. Each step up is truly a step up. There is zero reason to double jump someone needlessly. Especially if the Red Sox don't believe they need him in Boston this season.